The present invention relates generally to radar systems and more specifically to a waveform process for use with radar systems.
A Synthetic Aperture Radar (SAR) system is used for ground mapping even in poor weather conditions in which optical sensor cannot be used. Mapping range of SAR is generally longer than optical sensor and it can also be operated during night. Using SAR, desired resolution in azimuth is achieved by maintaining phase coherence between pulses and combining them in proper manner. The length of collected data (array length) is determined by desired azimuth resolution and collection geometry.
The following references disclose recent SAR systems that can be used with the present invention and the disclosures of which are incorporated herein by reference:                U.S. Pat. No. 6,492,932, SYSTEM AND METHOD FOR PROCESSING SQUINT MAPPED SYNTHETIC APERTURE RADAR DATA, invented by Jin, Michael        U.S. Pat. No. 6,255,981, METHOD FOR RANGE ALLIGNMENT AND ROTATION CORRECTION OF A HIGH RESOLUTION IMAGE IN AN INVERSE SYNTHETIC APERTURE RADAR SYSTEM, invented by Samaniego, Raymond        U.S. Pat. No. 5,430,445, SYNTHETIC APERTURE RADAR GUIDANCE SYSTEM AND METHOD OF OPERATING SAME, Peregrim, and        U.S. Pat. No. 5,424,742, SYNTHETIC APERTURE RADAR GUIDANCE SYSTEM AND METHOD OF OPERATING SAME, Long, Albert H.        
The above-cited references all describe SAR systems developed by Raytheon and which can use the present invention. The best reference is U.S. Pat. No. 5,430,445, SYNTHETIC APERTURE RADAR GUIDANCE SYSTEM AND METHOD OF OPERATING SAME, Peregrim, and this system uses a chirped signal provided by a chirp generator, and its performance can be improved, as discussed below.